Brace/bracket auto-close duplicates space character

[LeoniePhiline]

Using master @ eb49c5e, some change in helix' auto-closing behavior has made it a nuissance to type markdown checklists.

Example, trying to type a markdown list checkbox item - [ ]. The | character represents the insert cursor:

|
-|
- |
- [|]
- [ | ]

In the penultimate step, the bracket is auto-closed. This is fine.

In the last step, the space is duplicated, resulting in - [ ] (two spaces) rather than - [ ] (markdown list checkbox).

Is this a bug? Is this something that can be configured away?